<template>
  <div>
    <input type="checkbox" v-model="flag"> 全选 <button @click="fn">反选</button>
    <ul>
      <li v-for="item in arr" :key="item.name">
        <input type="checkbox" v-model="item.c"> <span> {{item.name}}</span>
      </li>
    </ul>
  </div>
</template>

<script>
export default {
  data() {
    return {
      arr: [
        {
          name: '猪八戒',
          c: false,
        },
        {
          name: '孙悟空',
          c: false,
        },
        {
          name: '唐僧',
          c: false,
        },
        {
          name: '白龙马',
          c: false,
        },
      ],
    }
  },
  methods:{
    fn(){
      this.arr.forEach(item => item.c = !item.c)
    }
  },
  computed:{
    flag:{
      get(){
        return this.arr.every(item => item.c)
      },
      set(val){
        this.arr.forEach(item => item.c = val)
      }
    }
  }

}
</script>

<style lang="less">
*{
  list-style: none;
  margin: 0;
  padding: 0;
}
div{
  margin-left: 10px;
  ul{
    li{
      line-height: 25px;
    }
  }
}
</style>
